tower



Dec 18 1923.

c. TGWEIR MAGNETO IGNITION SYSTEM Filed March 11, 1920 2 Sheets-Sheet 1H61 if W. W M

T0 DIST/Pl B0 70/? MAGNII'O GROUND/N6 TERM/MIL Afro/M 5) Dec. 18 1923.

C. H. TOWER MAGNETO IGNITION SYSTEM Filed March 11. 1920 2 Sheets-Sheet2 TO DISTRIBUTOR TO D/STR/d'l/TOR MAG/V570 GROUND/W6 WIRT/NG MO PatentedDec. 18, 1923.

UNITED STATES PATENT OFFICE.

CHARLES H. TOWER, OF CLEVELAND, OHIO, ASSIGNOR TO THE TEAGLE COMPANY, OFCLEVELAND, OHIO, A CORPORATION OF OHIO.

IAGNETO IGNITION SYSTEM.

Application filed March 11, 1920. Serial 1%. 385,080.

6 of Ohio, have invented certain new and useful Improvements in MagnetoIgnition Systems, of which the following is a specification.

The inventionrelates to a magneto ignition system of the type in whichan auxiliary source of current is used to give an intensified spark forstarting purposes.

In the majority of cases the only available or feasible auxiliary sourceof current is a battery which of course furnishes unidirectionalcurrent. In connecting the battery to the generating coil of the magnetoit is vitally important that the proper pole of the battery beconnected'to the ma neto terminal,

for if inadvertently or by mlstake the batter current is passed throughthe generator coi in the wrong direction the permanent magnets of thegenerator will be demagnetized. I have found in practice that this 2is'a serious difficulty.

The chief object of the present invention is to overcome the abovedifliculty, and this I accomplish by providing means that act automatically to prevent flow of the battery current in the wrongdirection through the generating winding of the magneto.

While my invention is applicable to various types of magnetos, I havedeveloped it and will here describe it in connection with an inductortype of high tension magneto having unidirectional flux through thegenerating winding, a generator of this kind being especially suited tothe use of an auxiliary current for starting.

Referring now to the accompanying drawin o a u ig. 1 showsdiagrammatically an ignition system embodying my improvements, the.sectional part of the diagram being taken on line 1-1 of Fig. 2.

Figs. :2 and 3 are a plan and a. side elevation, respectively, of thepolarized switch device slicwn in Fig. 1.

Fig. 4 shows diagrammatically another "form of ignition system embodyingthe in nomatically a modirated in Fig. 4.

llustratdiagra 0% c known form of inductor type of high tension magneto,only so much of the same being shown as is requisite for an understandmgof the present invention. The magneto comprises a combined base and polepiece 2, a top pole piece 3 having depending polar pro ections 3 and 3and straight bar permanent magnets 4, 4. Between the polar face of thepole piece 2 and the polar projections 3 and 3 is rotatably mounted anunwound inductor 5. On the polar projection 3 is arranged the hightension generating coil 6 comprising a primary section 6 and a secondary6.

One end of the secondary is grounded and the other end is connected tothe distributor gnot shown), as indicated. 7 is a condenser.

ne end of the low tension section of the winding is connected to oneterminal of the condenser, the other terminal thereof being grounded andalso connected to the fixed terminal8of the breaker mechanism. Themovable terminal 9 of said breaker mechanism is grounded as indicated.10 is the breaker cam. The other end of the low tension section of thegenerating winding is connectedto the magneto terminal 11 which inpractice is arranged at some convenient place on the outside of thegenerator frame or casing. 12 is a 3-position switch having electrodes12, 12*, 12 and 12 Electrode 12 is connected to the magneto terminal 11.Electrode 12 is connected to one terminal of a battery 13, the otherterminal of which is grounded. Electrode 12 is grounded. Electrodes 12and 12 are connected by conductors 14 and 15, respectively, to apolarized magnetically operated switch 16.

The switch 16 has a fixed electrode 17 to which conductor 14 isconnected and a separate electrode 18 to which conductor 15 isconnected. A movable contact block 19, designed to cooperate withelectrodes 17 and 18, is mounted on and insulated from a spring arm 20which is in turn carried by a cross bar 21 secured to the permanent manet- 22. The spring arm 20 normally hol s the contact block 19 out ofengagement with the electrodes 17 and 18 as indicated in Fig. 1. On thefree end of the spring arm 20 is secured a transversely arrangedarmature 23 for the magnet 22. Surronndin said armature 23 in inductiverelation t ereto are a pair of coils 24, These coils, which are series,have one terminal connected the conductor 15 and the otherterminalgrounded as indicated in Fig. 1. A current flowing through coils 24magnetizes the armature 23 and when the current flows in one directionthe polarity of the magnetized armature is such as to increase theattraction between it and the permanent magnet 22 and when the currentflows in the opposite direction is such as to decrease that attraction.When the magnetic attraction is increased as specified it is strongenough'to overcome the tension of the spring 20 and throw the switchblock 19 into engagement with the electrodes 17 and 18, thus closing theswitch. Dbviously if the current flows through coils 24 in a directionto decrease the magnetic attraction the switch 16 will not close.

The operation of the system above described will readily be understood.When the engine with which the system is used is being started and it isdesired to use the battery current to insure a strong ignition spark,the switch 12 is moved so as to connect electrodes 12 and 12 Thereuponthe current from the battery 13 flows through switch 12, conductor 15and coils 24 to ground. If the battery has been properly connected inthe system the current flowing through the coils 24 will be in .adirection to increase the magnetic attraction of the switch soias toconnect electrodes 17 and 18, whereupon the current flows through saidelectrodes, thence through conductor 14 to electrode 12 of switch 12 andthence to the magneto terminal 11 and through the low tension section ofthe magneto generating winding to the breaker and thence to ground. Whenthe breaker electrodes are open the interruption of the strong batterycurrent flowing through the primary of the coil results in thegeneration of an intense higlitension i ition current in the secondaryin the wel known manner. As soon as the engine is in operation switch 12is moved to connect electrodes 12 and 12 whereupon the battery isdisconnected and the low tension circuit of the generator is connectedto X ground, which is the normal running condition of the system.

If through inadvertence or mistake the battery 13 should have its wrongterminal connectedto the switch 12 then the battery current flowingthrough the coils 24 of the polarized switch would not eflect theclosing of the switch and as no spark could be obtained the driver wouldknow the connection was wrong and correct it. It will be seen that bythe use of the polarized switch 16 it is possible for the batterycurrent to flow to the generating winding of the magneto only in onedirection and if it is not connected to flow in this predetermineddirection actuation of the switch 12 is inedective. In other words, thepolarized switch 16 afiord an 1,4r7,rse

automatic control of the battery circuit which efiectively prevents anydemagnetizing of the permanent magnets of'the generator by the batterycurrent and, with a generator of the type shown, insures an actualmagnetizing action of the permanent magnets by the battery current.

Referring now to Fig. 4 of the drawings, 31 designates a magneto similarin every respect to that described above and comprising a bottom polepiece 32 and a top pole piece 33, depending polar projections 33' and33", permanent magnets 34, and inductor rotor 35, a high tensiongenerating winding 36, a condenser 37, fixed and movable breakerelectrodes 38 and 39 and breaker operating cam 40. 41 is the magnetoterminal exteriorly mounted on the generator as in the first describedconstruction.

The terminal 41 is connected to a 3-way switch 42. This switch has anoff position a in. which the generator circuit is open, a startingposition b in which the switch arm engages an electrode 42 and a runningposition 0 in which the switch armengages an electrode, 42 which isconnected to ground.

43 is a battery one terminal of which is grounded while its otherterminal is connected to a polarized magnetically operated switch 44,

The switch 44 has an electrode 45 con.- nected to the battery 43, anelectrode 46 connected to the electrode 42 of the switch 42 and amovablecontact 47 adapted by its movement to connect and disconnectelectrodes 45 and 46. The contact 47 is mounted on and insulated from apivoted iron bar 48 which is arranged between the poles of a permanentmagnet 49. A coiled spring 50 serves to normally hold the pivoted bar 48against a stop 51 with the contact 47 out of engagement with theelectrodes 45 and 46. The bar 48 is surrounded by a coil 52 which hasone of its terminals grounded and its other terminal connected through amanual switch 53 with the battery 43. 54 is a starting motor which hasone terminal grounded and the other terminal connected into the circuitbetween the coil 52 of the polarized switch and the manual switch 53.

From the above descri tion the operation of the system shown in ig. 4will readil be followed. In starting the engine with which the system isused, the 3-way switch 42 is first moved to the position b and then uponclosing the starting switch 53 current from the battery flows to thestarting motor 54 which turns the engine over, and also flows throughthe coil 52 of the polarized switch 44. Current flowing through coil 52magnetizes the bar 48 and, if the proper terminal of the battery hasbeen connected with said coil 52, the attraction between the bar 48 andthe south pole of the magnet 49 is suficient to overcome the tension ofthe spring 50 and move the switch contact 47 into engagement with theelectrodes 45 and 46, whereupon the current flows from the batterythrough the switch 44 and switch 42 to the low tension section of thegenerating winding 36 of the magneto. Thus when the magneto circuit isopened by the breaker a very strong high tension ignition current isgenerated. As soon as the engine is in satisfactory operation thestarting switch 53 is opened and the 3-way switch 42 is moved toposition 0 whereupon the magneto operates on its self-generated currentin the normal manner.

If the battery 43 should have its wrong terminal connected with thepolarized switch 44 the battery current flowing through the switch coil52 will magnetize the iron bar 48 in such a way that the magneticattraction is added to the tension of the spring 52 and the switchcontact 47 is held away from the electrodes 45 and 46 sothat with theswitch 42 in position b no spark can be secured when the engine isturned and the driver will know that the battery is not properlyconnected.

In Fig. 5 of the drawing is shown a modification of the system shown inFig. 4 the modification consisting in some changes in the connections ofthe magneto generating winding and also in the introduction into thebattery circuit of a vibrator. In this modified construction 61represents the generating winding of the magneto. The low tensionsection 61 of the generating winding has one of its terminals groundedas indicated while its other terminal is connected to a socalledgrounding terminal of the magneto and thence to the fixed electrode ofbreaker 62, the movable electrode of said breaker being grounded asindicated. The high tension section 61 of the generating winding has oneterminal grounded and its other terminal leading to the distributor asin the previously described forms of construction. The groundingterminal of the magneto is connected to a 3-way switch 63 which has agrounded electrode 63* and an electrode 63 which is connected to oneterminal of an 'electro-magnetic vibrator 64. The other .rent flows fromthe battery through switch 44, vibrator 64 and switch 63 to thegrounding terminal of the magneto. Thence, if the breaker electrodes areclosed the current flows through the breaker to ground. Then upon theopening of the breaker the rapidly pulsating current pames through thelow tension section 61 of the magneto generating coil and generates arapid succession of high tension ignition currents in the secondary 61".

It will be seen that the vibrator 64, which may be of any suitable formof construction, performs th customary function of a vibrator inconnection with a magneto, but by combining it with my improvedpolarized switch device I effectively prevent demagnetization of thepermanent magnets of the generator by the battery current.

The novel features of my improved systern can be embodied in a greatvariety of structural forms. For example, the polarized switch of thesystem can be combined with the manual switch 12 (or 42) in such a Wayas to produce a compact unit. Again, the polarized switch can be builtinto the magneto itself. I have not shown these particular features andstructural matters as they will constitute the subjects matter ofseparate applications. In other respects my improved system is subjectto variation and it will be understood that the arrangements indicatedin the drawings are only for purposes of illustration and explanation,the scope of the invention being indicated in the appended claims.

Vhat I claim is,

1. In an ignition system, the combination of an ignition currentgenerator having permanent field magnets, an auxiliary source of currentadapted to supply unidirectional current, manual means for connectingthe generating winding of the generator to said auxiliar source ofcurrent, and automatic switch evices having means f r yieldingly holdingthe switch open and e ectromagnetic means energized by current from saidauxiliary source and adapted only when said current flows in apredetermined direction to close said switch.

2. In an ignition system, the combination of an ignition currentgenerator having permanent field magnets, an auxiliary source of currentadapted to sup 1y unidirectional current, manual means tbr connectingthe generating winding of the generator to said auxiliary source ofcurrent, and automatic switch devices having means for yieldinglyholding the switch open, a permanent magnet, an armature for said magnetconnected to the switch contact, and a winding in circuit with theauxiliary source of current supply and inductively related to thearmature, whereby when the current flows; in a predetermined directionthrough the last named winding the switch is closed but is not closedwhen said cufr'ent fiowsin the opposite direction.

In testimony whereof. Lhereunto afiix my signature.

CHARLES H. TOWER.

